<template lang="">
    <el-container class="home_container">
        <!-- 头部区域 -->
        <el-header>
            <div class="logo">
                <img src="../assets/logo.png" alt="">
                <span>电商后台管理系统</span>
            </div>
            <el-button type="info" @click="logout">退出</el-button>
        </el-header>
        <!-- 页面主体区域 -->
        <el-container>
            <!-- 侧边栏 -->
            <el-aside :width="isCollapse?'64px':'200px'">
                <div class="toggle-button" @click="toggleCollapse">|||</div>

                <!-- 侧边栏菜单区域 -->
                <!-- 
                    router  使用 vue-router 的模式，在激活导航时以 index 作为 path 进行路由跳转
                    default-active          当前激活菜单的 index  刷新之后还能跳转到这个菜单
                    collapse                是否折叠 true/false
                    unique-opened           是否只保持一个子菜单的展开
                    collapse-transition     是否开启折叠动画
                -->
                <el-menu background-color="#fff" text-color="#303133" active-text-color="#409eff" unique-opened
                    :collapse="isCollapse" :collapse-transition="false" router :default-active="activePath">
                    <el-menu-item @click="saveNavState('/welcome')">
                        <i class="iconfont icon-shouye"></i>
                        <span>首页</span>
                    </el-menu-item>

                    <!-- 一级菜单 -->
                    <el-submenu :index="item.id+''" v-for="item in menuList" :key="item.id">
                        <!-- 一级菜单模板区域 -->
                        <template slot="title">
                            <!-- 图标 -->
                            <i :class="iconsObj[item.id]"></i>
                            <!-- 文本 -->
                            <span>{{item.authName}}</span>
                        </template>

                        <!-- 二级菜单 -->
                        <el-menu-item :index="'/'+subItem.path" v-for="subItem in item.children" :key="subItem.id"
                            @click="saveNavState('/'+subItem.path)">
                            <!-- 二级菜单模板区域 -->
                            <template slot="title">
                                <!-- 图标 -->
                                <i class="el-icon-menu"></i>
                                <!-- 文本 -->
                                <span>{{subItem.authName}}</span>
                            </template>
                        </el-menu-item>
                    </el-submenu>
                </el-menu>


            </el-aside>
            <!-- 右侧内容主体 -->
            <el-main>
                <!-- 路由占位符 -->
                <router-view></router-view>
            </el-main>
        </el-container>
    </el-container>
</template>
<script>
    export default {
        name: 'Home',
        data() {
            return {
                // 左侧菜单数据
                menuList: [],
                iconsObj: {
                    '125': 'iconfont icon-users',
                    '103': 'iconfont icon-tijikongjian',
                    '101': 'iconfont icon-shangpin',
                    '102': 'iconfont icon-danju',
                    '145': 'iconfont icon-baobiao'
                },
                // 是否折叠
                isCollapse: false,
                // 被激活的链接地址
                activePath: ''
            }
        },
        created() {
            this.getMenuList()
            this.activePath = window.sessionStorage.getItem('activePath')
            // console.log('activePath' + this.activePath);
        },
        methods: {
            logout() {
                // 清空缓存 把地址转到/login
                window.sessionStorage.clear()
                this.$router.push('/login') // 编程式导航
            },
            // 获取所有的菜单
            async getMenuList() {
                const { data: res } = await this.$http.get('menus')
                // 通过 $http 发起 ajax请求 看 main.js
                // 向服务器发出一个HTTP GET请求，获取一个名为menus的资源，并返回一个Promise
                if (res.meta.status !== 200) return this.$message.error(res.meta.msg)
                this.menuList = res.data
                // console.log(res);
                // console.log(this.menuList);
            },
            // 点击按钮 切换菜单的折叠与展开
            toggleCollapse() {
                this.isCollapse = !this.isCollapse
            },
            // 保存链接的激活状态
            saveNavState(activePath) {
                window.sessionStorage.setItem('activePath', activePath)
                this.activePath = activePath
                if (activePath === '/welcome') {
                    this.welcome()
                }
            },

            welcome() {
                this.$router.push('/welcome')
            }
        }
    }
</script>
<style scoped>
    .home_container {
        height: 100%;
    }

    .el-header {
        background-color: #766ce8;
        display: flex;
        justify-content: space-between;
        align-items: center;
        color: #fff;
        font-size: 20px;
        text-align: center;
        line-height: 60px;
        font-weight: 400;
    }

    .el-header .logo {
        display: flex;
        align-items: center;
    }

    .el-header .logo img {
        width: 40px;
        height: 40px;
        padding-right: 20px;
    }

    .el-aside {
        background-color: #fff;
    }

    .el-aside .el-menu {
        border-right: none;
    }

    .el-main {
        background-color: #Eaedf1;
        color: #fff;
        font-size: 20px;
        /* padding: 0; */
    }

    .iconfont {
        margin-right: 10px;
    }

    .toggle-button {
        /* background-color: #a49fe3; */
        color: #a49fe3;
        font-size: 10px;
        font-weight: 600;
        line-height: 24px;
        text-align: center;
        letter-spacing: 0.2em;
        cursor: pointer;
    }
</style>